Expression of Bcl-2 but not Bax or p53 correlates with in vitro resistanceto a series of anticancer drugs in breast carcinoma

Programmed cell death is an important determinant of the response to chemot herapy. Among the factors controlling this process, a significant role is p layed by bcl-2, bax and p53. The in vitro chemosensitivity of the 177 breas t carcinomas was assessed by the histoculture drug response assay (HDRA) us ing mitomycin C (MMC), 5-fluorouracil (5-Fu), adriamycin (ADM), cisplatin ( CDDP), and cyclophosphamide (CPA). The susceptibility of Bcl-2-negative tum ors to all the drugs killing was significantly higher than that of Bcl-2-po sitive tumors. No relationship between Bax or p53 immunoreactivity and sens itivity for any of anticancer drugs studied was demonstrated. Immunohistoch emical results regarding Bcl-2 are promising in the evaluation of the sensi tivity of cancer cells to a series of anticancer drugs and might be therape utically useful as an indicator of response to adjuvant chemotherapy for br east cancer.